function dx=Plant(t,x,flag,para)
dx(1)=0;

d=para(1);
y=para(2);
dy=para(3);

dx(1)=-2500*x(1)-4*sign(x(1))-0.5*x(1)^(5/9)-abs(-2*y+3*(1-y^2)*dy)*sign(x(1))-(-2*y+3*(1-y^2)*dy)-d;

